磷在氧化锆-碳纳米管复合材料上的吸附研究

摘要

采用水热合成法成功制备了氧化锆-碳纳米管复合材料,并研究了对磷的吸附行为.表征结果表明,碳纳米管经氧化锆修饰后仍具备介孔结构；氧化锆粒子可均匀分散在碳纳米管表面.吸附实验结果表明,氧化锆粒子的粒径越小,氧化锆对磷的标化平衡吸附量越高,吸附速率越快.磷在氧化锆-碳纳米管复合材料上的吸附等温线符合Freundlich等温吸附模式,属于优先吸附,吸附动力学可用拟二级动力学模型描述.降低离子强度和溶液pH可促进磷的吸附,共存离子对磷吸附具有抑制作用,影响顺序依次为F-＞NO3-≈SO42-,其中F-影响最大,NO3-和SO42-次之.%Zirconia functionaiized multi-walled carbon nanotubes were successfully synthesized by hydrothermal method and their adsorption behavior for phosphate were also investigated. Characterized results showed that the BET surface areas and the total pore volumes of MWNTs decreased greatly after ZrO2 functionalization. The average particle size of zirconia that uniformly dispersed on the surface of MWNTs increased with increasing ZrO2 content. Phosphate adsorption experimental results showed that decreasing ZrO2 particle size was beneficial to improve the ZrO2 content-normalized adsorption amount and the adsorption rate. The adsorption isotherm could be well fitted by Freundlich equation which suggested a preferential adsorption, while kinetics followed the pseudo-second-order model. Lower ionic strength and pH were favorable to the removal of phosphate. And the effect of co-existing anions was in the order of F>NO3-≈SO42-.